This invention relates to a rack device which is provided with drive members and mounted at the side wall of a face conveyor or a spill plate for guiding and moving a mining machine, particularly a drum-cutter type mining machine. The rack device is drivingly engaged by means of at least one driven sprocket wheel or with at least one endless circulating drive chain coupled to a drive shaft on the mining machine.
It is known in the art in regard to chain-driven coal cutters to produce their advancing motion by means of a rope which is coiled about a pulley. The rope drives a transmission on the coal cutter which includes a gearwheel forming means engageable with a rack to move the drum cutter along the working face of a mine. The rack comprises a channel section arranged so that its side members face the floor. The web section is provided with a series of apertures arranged at spaced-apart locations along the length of the channel. The gearwheel, driven by the transmission on the chain coal cutter, has teeth which engage the apertures in the web section to propel the machine along the channel section.
It is also known in the art to arrange an angle trough for guiding a drum cutter along the mine face. A vertically-arranged member of the angle trough is mounted onto a conveyor at its side wall nearest the working face of the mine. The vertically-arranged member is bent along its top edge toward the coal face so that the bent edge together with an approximately Z-shaped cross-sectional strip, form a box-shaped trough which is open at its top. A flat-link chain, resiliently mounted at both ends, is situated in the trough and positively retained therein by the horizontally-arranged top edge of the strip and by the vertical faces of the angle trough member. The construction is such as to prevent the flat-link chain from lifting out of the trough. The drum cutter engages, by means of two driven chain sprockets, the flat-link chain which functions in this instance as a rack, to move the cutter machine along the coal face.
A spill plate for chain scraper converyors is also known in the art where the spill plate consists of individual sections having equal lengths with each length corresponding to the length of the scraper chain conveyor sections to which it is attached. The joints between the spill plate sections are offset by approximately half the length of a trough section to enable the spill plates to be utilized for stiffening the conveyor. The conveyor may take the form of a loader conveyor which is situated in the gallery.
In the initially-described form of known rack, the individual sections are joined to each other by permanently riveting fishplates onto both sides of the rack at the joints. The known form of rack described thereafter comprises a flat-link chain which is stretched along the entire length of the angle trough and is resiliently retained at both ends. The first-mentioned rack configuration is for all practical purposes rigid and is not adaptable to follow along the run of a floor or accommodate continuous resetting or advancing motion of the face conveyor. On the other hand, when a rack is formed by a flat-link chain, the rack is capable of adapting itself to the shape of the floor but it is immovable in the horizontal direction and is, therefore, not very suitable for use with a face conveyor adapted for advancing movement.